A project might have a default diagram. If set, this diagram loads when Enterprise Architect first opens the model. It is often convenient to place hyperlinks to other diagrams and resources on the default diagram, thus creating a Home Page for your model.
To set the currently active diagram as the model default, select the Diagram | Set as Model Default menu option.
Tip: Once you have specified a default diagram, the Home icon on the diagram toolbar takes you to that diagram.